The present invention relates to superconducting bearing devices having incorporated therein a superconductor permitting penetration of a magnetic flux thereinto.
Superconducting bearing devices heretofore known include, for example, the one disclosed in Unexamined Japanese Patent Publication SHO 63-243523.
The superconducting bearing device disclosed includes a Type I superconductor, i.e., a superconductor preventing the penetration of magnetic flux perfectly to utilize the perfect diamagnetism of the superconductor. The device comprises a rotary shaft made of the superconductor and having its opposite ends fitted in a pair of recesses each of which is formed in a support member of magnetic material magnetized to one of the polarities, the rotary shaft being supported in a non-contacting position axially thereof.
With the known superconducting bearing device, the rotaty shaft is supported in a non-contacting position utilizing perfect diamagnetism as stated above and is therefore instable with respect to a direction orthogonal to the direction of repulsion, so that the support member for supporting each end of the rotary shaft must be machined to a shape surrounding the shaft end. Furthermore,between the shaft end and the support member, the portion opposed to the shaft end axially and radially of the shaft needs to be magnetized. Accordingly, the device is cumbersome to design and make.